Multicolor preview looks very different to expected

#1

Hello - I am keen to go ahead and print a multicolour model, but the preview looks very different to what I expected.

The model should be almost entirely black, with a small red stripe, but when I upload the model and choose multicolour, the preview has the colours everywhere. The preview looks pretty cool with all the colours everywhere, but just wanted to check what will actually be printed - what my software shows, or what the i.materialise preview shows?

I’ve attached the i.materialise online preview versus what my desktop software shows so you can see the discrepancy.

Thanks so much for your help.

preview
preview2363×1182 417 KB

#2

Have you checked the actual output file produced by your desktop software with an external viewer like view3dscene to make sure that the texturing is correct ?
Apart from bugs in the export module of your software, this problem can also occur if the underlying geometry is not 2-manifold - any automatic fixing performed by the site software will need to add or remove vertices to repair defects, but it cannot easily update the texture coordinates to match the changed vertex count.

#3

Thanks! It looks OK in MeshMixer and MeshLab, but then fails in view3dscene. I’ll have a look at the underlying geometry to see if that can explain it!

Thanks for your help.

#4

As mkroeker already said; it probably has something to do with the export settings and the file format you used. Some file formats are able to include textures directly in the file (e.g. colored STL, VRML, SKP, and dae), while others store the texture in a separate image file and map file (this is the case for obj).

In the latter case (obj files), it’s important to remember that an obj file alone only has the information about the model’s shape and volume. It’s a mesh without any texture information. For printing in color, you also need to save a mapping file (mtl), which tells the printer where the colors and texture information should go.

If you have used texture images (for example, png files), they must also be included in the upload. Simply group all files related to the model in a zip file and upload it to our website. Our viewer still won’t show the texture, but we’ll have all of the information we need to print the model the way you want it.

Perhaps you can find some more tips on https://i.materialise.com/blog/en/perfect-multicolor-plus-3d-printing/

Kind regards Lizy

#5

Hi Peter,
We are able to see the color when opening it up in our printing software.
The viewer nor the model-image generator have difficulties showing it.
The model has some areas that are too thin to print (see below)
20-01-2020 10-01-17

20-01-2020 10-20-59
20-01-2020 10-20-59878×454 94.7 KB

#6

Thanks so much for your feedback and advice.

That blog post helps a lot - although it seems .obj files can include colour, in meshmixer I exported as “.obj format with per-vertex colour” but I will try one of the other supported formats.

And thanks Wim, sounds like the printing software accepts this format OK - and thanks so much for checking the thickness, I will thicken a little then I think I am good to go :slight_smile:

Thanks again for all your help and advice!

#7

"Apart from bugs in the export module’…I see what you did there…lol